For over nine thousand years, cities have played an important role in human development.

Jericho, the oldest city on record with a population of 2,000, was a center of commerce and learning. So was Uruk, Mari and other great cities through history to Tokyo, which is the largest city today.

Determining the population of any city prior to the late 1700's is no easy task. Even the most casual census was unheard of before then, and studies to nail down city populations throughout history weren't even attempted until 1944.

It was then that Tertius Chandler and Gerald Fox undertook a 30 year study, completed in 1974, that looked at urban population in 2,000 cities, over several thousand years.

The numbers were drawn from the size of a city's military in peacetime and in war, household data, agricultural commerce, church records, fortification sizes, food distribution, loss of life in a disaster, and city comparisons. Chandler revised his opus in 1987, applying greater detail and further research to his numbers.

In 2003, George Modelski expanded on Chandler's work and wrote World Cities, -3,000 to 2,000. The book remains the authoritative reference on historic population today.

The data here is all based on Modelski's numbers, except for London in 1825 which is Chandler. Jericho and Uruk, the two most ancient cities, are based on estimates made from Modelski's work.